Hydrocarbon treatment



Patented July 10, 1945 nYDRooARBoN TREATMENT Stewart C. Fulton,Elizabeth, and Thomas Cross,

Jr., Union, N. J assignors to Standard Oil Development Company, acorporation of Delaware N Drawing. Application March 5, 1942,

Serial No. 433,484

2 Claims.

The present application is a continuation-inpart of our copendingapplication, Serial No. 296,919, filed September 28, 1939, now U. S.Patent 2,363,858 which in turn is a continuation-inpart of our SerialNo. 55,234, filed December 19, 1935, now Patent No. 2,204,673.

The present invention relates to novel methods of convertinghydrocarbons into desired products, and more particularly relates toimproved methods for reforming gasoline and naphthas in the presence ofa catalyst comprising aluminum chloride supported on a material such asActivatecl Alumina or silica gel.

As is generally known, a tremendous amount of research has been directedin the last few years toward the production of high octane numbergasoline. This research has resulted in the development of processessuch as the alkylation of isoparaflins with olefins to produce branchedchain hydrocarbons boiling within the gasoline range, which productshave very high anti-detonation qualities. Other methods of improving theoctane rating of gasolines and naphthas involve reforming the gasolineor naphthas usually in the presence of a catalyst and added hydrogen.

The present invention is directed toward improving the quality ofnaphthas and gasoline by a reforming operation carried out in thepresence of a catalyst comprising aluminum chloride supported on silicagel or Activated Alumina, the catalyst having the property of beingstable at temperatures above the volatilization temperature of aluminumchloride against the loss of the said aluminum chloride.

In order to afford a better understanding of our invention, thefollowing specific examples setting forth preferred embodiments ofourinvention are given below:

Example 1 An East Texas heavy naphtha (B. P. about 250-400 F.) wascontacted at a temperature of about 420 F. and a feed rate of about 0.5cc.

per gram of catalyst per hour with a catalyst comprising about 8%substantially anhydrous A1Cl3 on silica gel. The catalyst may beprepared by forming a silica gel by Well known methods, drying the gel,which may be in the form of pills, extruded lengths, granules or thelike, and thereafter impregnating thegel with a solution or slurry ofaluminum chloride in ethylene dichloride. The ethylene dichloride andany excess AlCls not absorbed is removed by heating the catalystpreferably in a stream of inert gas such as N2. The liquid productresulting from this re-.

forming operation showed an octane number improvement of 9.0 (C. F. R.).Upon analysis it was shown that 2.9% by weight of gas was formed, whichgas consisted mainly of isobutane. This example tends to show, amongother things, that the reforming of naphtha catalytically involves theisomerization of hydrcarbons.

Example 2 Example 3 A light East Texas naphtha having a final or an endpoint of about 250 F. is reformed over a catalyst comprisingsubstantially anhydrous AlCl3 supported on silica gel. Using conditionssimilar to Example 1 results in an octane number improvement of aboutthe same order. As in the case of the lower temperature operation, thegas formed is substantially isobutane.

Instead of impregnating the carrier with a slurry or solution ofaluminum chloride in a halogenated hydrocarbon or other non-aqueoussolvent, we may treat the silica gel or the alumina with vaporizedaluminum chloride. Preferably, this is accomplished by heating thealuminum chloride to vaporize the same, then mixing it with a carriergas such as N2, 002, flue gas, etc., and forcing the mixture through aheated mass of silica'gel or alumina. The aluminum chloride is adsorbedby the silica gel or alumina in a state Where it is stable againstvolatilization above the vapor point of the said aluminum chloride. Uponsaturation of the silica gel or alumina with aluminum chloride in themanner indicated, the carrier is treated with an inert gas such as N2,CO2, etc., to remove unbound or removable aluminum chloride. This methodof impregnation isdescribed in detail in the application of J. H.Bartlett, Serial No. 415,235, filed October 14, 1941.

Our invention refers to improved methods of reforming naphthas and thegist of the invention is in the new catalyst employed for this purpose.We may according to our process reform either light or heavy naphtha ora whole gasoline fraction according to the methods hereinbefore setforth, i. e., the anhydrous impregnation of the silica gel or thealumina with the aluminum chloride and also in the absence of substanceswhich will react with the aluminum chloride chemically, such asalcohols, ethers, etc.

In reforming naphthas or gasoline, the temperature employed may be fromabout 350 F. to 950 F. or higher, the feed rates of oil to the reactionzone may vary from 0.1 to 10 volumes of 10 oil per volume of catalystper hour on a cold oil basis, and the'pressure may be from belowatmospheric to 200 to 300 lbs. per square inch gauge. Hydrogen may bemixed with the feed stock in the amount of from 20 to 80 mol per centhydro- 15 gen of the hydrocarbon feed stock.

Many modifications of our invention not specifically mentioned hereinwill readily suggest themselves to those familiar with the present art.

We claim:

1. The process of reforming naphtha which comprises contacting saidnaphtha at reforming temperatures with a catalyst prepared byimpregnating an activated solid adsorbent with alu- 1 minum chloridevapors contained in a carrier gas and then heating the mass with aninert gas to remove unadsorbed aluminum chloride.

2. A process according to claim 1 in which the activated solid adsorbentis activated silica gel.

STEWART C. FULTON. THOMAS CROSS, JR.

